This invention relates generally to an apparatus for preparing flitches for the manufacture of wood veneer; and, more particularly, to a method and apparatus for automatically planing flitches.
Wood veneer is made by slicing pre-conditioned logs (or half-logs), commonly called xe2x80x9cflitchesxe2x80x9d. A flitch is xe2x80x9chalf a logxe2x80x9d and is made by cutting the log in half longitudinally. Prior to slicing, the flitch is soaked in water. As a result of the cutting and soaking, warpage occurs, making it necessary to plane the flitch prior to slicing. The flitch is planed in order that smooth surfaces are presented to the slicing apparatus. In the slicer, the flitch is held by a holding device, such as the vacuum holding device described in U.S. Pat. No. 5,385,184. A flat flitch surface facing the holding device ensures a better hold. A flat flitch surface opposite the holding device ensures better quality veneer.
In planing a flitch, it is desired to maximize the yield and minimize the amount of waste. Presently, planing is done manually, with no measurements made either before or during the planing operation. Moreover, presently, planing is done using a straight blade that is manually adjustable in xe2x85x9 or xc2xc inch intervals. Measurements during planing are presently typically done xe2x80x9cby eyexe2x80x9d, i.e., an operator determines when the flitch has been properly planed. If any measurements of the flitch are taken at all, they are taken manually. Usually, no measurements are taken either before or after the planing operation. As a result, present planing techniques and machines result in wasted material.
What is needed, then, is a machine and method for planing flitches that maximizes yield and minimizes waste.
The invention broadly comprises a method and apparatus for automatically planing a flitch. The method of the invention comprises measuring the distance between the top and bottom surfaces of the flitch, and the linearity of those surfaces, at a plurality of longitudinally spaced locations, calculating a planing operation of the flitch based upon the plurality of distance measurements; and then planing the flitch according to the calculation. In a preferred embodiment, the measurements are taken by a bank of photodetectors in combination with a computer (microprocessor). The calculation is done by the microprocessor. The apparatus of the invention comprises means for making a plurality of distance measurements between a first generally planar surface of the flitch and a second generally frustoconical surface of the flitch, means for calculating a planing operation for the flitch based upon the measurements, and, means for planing the flitch in accordance with the calculations. A variety of different types of planing heads can be used to do the actual planing, and the invention is not limited to any particular type or number of planing heads. The invention is capable of cutting stepped groves in the bottom surface of the flitch to enable more stable veneer slicing on rotary cutters.
A primary object of the invention is to provide a method and apparatus for automatically planing a flitch so as to maximize yield and minimize waste.
A secondary object of the invention is to automate the flitch planing operation to expedite the operation and minimize human error and intervention.
A further object of the invention is to provide stepwise planing of flitches to prevent breakage of veneer tips presently caused by continuous planing methods.
Another object of the present invention is to provide a method and machine for creating stepped grooves within a bottom surface of a flitch to accommodate more stable holding of the flitch when performing rotary veneer cutting operations.
These and other objects, features and advantages of the present invention will become readily apparent to those having ordinary skill in the art in view of the following detailed description in view of the several drawing figures and appended claims.